1. Field of the Invention
The present invention relates to an organic electroluminescent display device.
2. Description of the Related Art
In many organic electroluminescent display devices, a planarization film is formed on a circuit including wires and TFTs (thin Film Transistors), and an organic layer including pixel electrodes and a light-emitting layer is formed on the planarization film. A common electrode is formed on the organic layer. Since the planarization film is formed of an organic material, the planarization film may serve as a permeation path of moisture. When moisture passes through the planarization film and reaches the organic layer, the organic layer is degraded.
In JP 2004-335267 A, a groove located in an area (peripheral area) on the outside of a display area is formed in the planarization film. The permeation path of moisture into the display area is blocked by this groove. In JP 2006-302860 A, the planarization film (organic material film 10) is separated for each of pixels, so that a diffusion path of moisture is blocked.
The organic electroluminescent display device includes, in the peripheral area, a circuit including TFTs and constituting a shift register or the like (this circuit is hereinafter referred to as “peripheral circuit”). The peripheral circuit is also covered by the planarization film. However, when the above-described groove for blocking the permeation path of moisture is formed in the planarization film, the peripheral circuit cannot be formed at the position of the groove. Therefore, the width of the peripheral area is increased by an amount corresponding to the width of the groove. This constitutes a limitation on narrowing a peripheral area portion of the organic electroluminescent display device.